Low-Barrier, Dendrite-Free, and Stable Na Plating/Stripping Enabled by Gradient Sodiophilic Carbon Skeleton

Na metal anodes have attracted widespread attention due to their ultrahigh specific capacity, low redox potential as well as the huge abundance and ubiquitous distribution of sodium resources. However, the practical application of Na metal anodes is largely hindered by their poor cycling stability and safety issues, mainly caused by the uneven deposition and terrible dendrite growth of metallic Na. To regulate the Na deposition behavior and direct uniform plating, herein, a gradient sodiophilic carbon skeleton prompted by the difference in the disorder degree and defect concentration is proposed. These extraordinary features render the as-proposed structure a promising accommodation for metallic Na, with a low nucleation overpotential of only 11.1 mV at 10 mA cm(-2) and a small polarization voltage of 12 mV at 5 mA cm(-2) in symmetric batteries. Impressively, the resultant structure reveals outstanding advantages in suppressing Na dendrites and thus enables a dendrite-free Na metal anode. The findings gained in this work provide solutions to construct stable and dendrite-free Na metal anodes through tailoring the Na deposition behavior.

Automated summary

The gradient sodiophilic carbon skeleton proposed in this study effectively regulates the sodium deposition behavior, achieving uniform plating and enhancing stability and safety, significantly reducing the risk of dendrite growth.